Henby s



AH. S..MILLBR DentalPlugger and Burr'.

No. 238,950. Patented March15,1s8|.

NAPETEHS. FHOTOvLITHoGRAPHER. WASNINGION. D. Q.

UNITED STATES l PATENT OEETCE.

i HENRY S. MILLER, OF ROCHESTER, NEW YORK.

DENTAL PLUGGER AND BURR.

SPECIFICATION forming part Of Letters VEateIlt N0. 238,950, dated. March15, 1881.

` Application mea March 17,1880. (Model.)

To all whom it may concern:

Be it known that I, HENRY S. MILLER, a citizen of the United States,residing at Rochester, Monroe county, New York, have invented a certainnen7 and useful Improvement in Dental Burrin g and Plugging Instruments;and I do hereby declare that the followingis a full, clear, and exactdescription of the same, reference being had to the accompanyingdrawings, in which' Figure l is a central longitudinal section of theinstrument arranged as a burring-instrnment. Figs.l2, 3, 4, and 5 aredetail views of the same. Fig. 6 is an enlarged section of the operatingend arranged as a plugging-instrument. l y y My improvement relates tocombined burring and plugging instruments 'which can be connected with adental engine, by which rotary motion is imparted, and which canbeconverted from one use to the other by the employment of an engaging anddisengaging device that is under control of the operators finger.

The invention consists in the construction and arrangement of Apartshereinafter more fully described and claimed. y

In the drawings, A represents thecylindrical body of the instrument,which is of usual form.

B is a small shaft or spindle, which extends through the cylinder andprojects at the rear end, as shown at a, and is connected with thedental engine in a well-known way, so that rotary motion is imparted'to`the spindle.

G is a plug or bearing screwingin to the rear end of the cylinder, andforming the bearing for the spindle at that point, the spindle beingretained against end movement by` shoulders b b.

D is a mallet or hammer, which slides free on the spindle within thecase.

E is a coiled spring, which fits around the spindle and bears upon themallet.

F is a collar, which rests against the spring, and Gr is a nut formingafollower, which screws up and down upon a thread cut on the spindie andbears against the collar. This nut has a slot, c, like a screw-slot, andwith this slot engages the bit d of a spring, H, which is pressed downby the finger of the operator.

When so pressed down the spring holds the nut from turning, and thespindle turning therein causes the nut to move, down on thescrew-thread, thereby compressing the spring and increasing the force ofthe blow of the mallet.

I is the burring-tool, which enters a socket at the end of the spindle,and is secured in place by the following means: The shank end of thebarring-tool is notched out, as shown at f, Fig. 5, leaving aright-angled offset lug, g. The bottom of this end is also squared oriiattened, as shown ath. The body of the spindle is provided with` alongitudinal groove, z', and on one side of this is an offset notch, k.When the shank of the barring-tool is inserted in the socket of thespindle, the lug g cornes opposi tethe notch la, and by turning the toolaxially i thelug strikes into the notch.

K is a locking piece or key which rests in the groove It has aprojecting point,l, which enters a hole in the mallet, and it also has ahorizontal extension, m., of such size and form as to slide under theattened end, h, of the burring-tool shank, and thus'prevent it fromturning when the lug g is locked in the notch k, as before described.The locking-piece K rides up and down with the mallet, its end m slidingup and down under the'iiattened end li, and the locking-piece alsoserves4 to keep the mallet from turning by resting in the groove i. Whenthe mallet is raised to its highest point, the end m is freed from thetool-shank, and the latter can then be removed by turning it back, so asto free it from the notch la and drawing it out. If desired, the malletmay havean additional spline orfeather to keep it from turning. This isa simple and convenient device for lockin g the tool in place andkeeping the mallet from turning axially, as the tool is thereby renderedperfectly stiff and solid, and the exterior surface of the spindle isleft flush for theipassage of the mallet. The locking-piece is easilyengaged and disengaged. A cam is formed near the lower end of themallet, consisting of an inclined shoulder, n, and a vertical abruptoffset, u', to same, as shown in Figs. 2 and 3.

Il is a linger-piece, having a lug, p, which is capable of engagementwith or disengagement from the cam. It is preferably made in IOO ' theform of a spring, as shown, so that when pressed down by the finger itwill engage with the cam, but when released it will rise out ofengagement. When the finger-piece is pressed down so as to engage withthe cam, the latter will ride upon the finger-piece as it rotates, andwill alternately rise and fall, thereby producing a sharp blow orconcussion.

If desired, the lug of the finger-piece may h ave a small friction-wheelwhich bears against the shoulder of the cam, and the sides of the malletmay also have small friction rollers, which travel on the interior ofthe case A, the object being to decrease friction.

When the instrument is used as a plugger, the burring-instrument isremoved and a plugger, J, is employed. It is attached in the followingmanner:

Y M is a hollo7 socket which is screwed into the front end of case A.

N is a tube which slides freely but accurately within this socket, andhas a stroke sufficient to produce the necessary concussion in plugging.On the inner end of the tube is a shoulder, s, which rests in contactwith the mallet, and at the outer end is a socket, t, into which screwsthe plugging-tool J. The socket and tube remain attached to the case atall times, and it is only necessary to change the tools or points tochange the work.

rlhe operation is as follows: The instrument is connected with thedental engine, and the shaft B receives a continuous rotary movement,carrying with it the nut c, the collar F,

spring E, mallet D, and burring-tool I. To convert the instrument into aplugger the tools are changed, and the nger-piece L is pressed down toengage with the cam on the mallet, which causes the latter to rise andfall and produce blows upon the plugger. The whole is accomplished by asimple rotary movement of the spindle, and saves the necessity of twoseparate and independent instruments for the purposes. The same effectmay be produced 'by making the spindle B in sections, or intwo` or moreseparate lengths, and connecting themv by slides or other engaging anddisengaging connections.

One special advantage consists in the use of the engaging anddisengaging device L, by which, when the instraiment is used as aplugger, the motion of the mallet can be controlled at pleasure, eitherby pressing said device down to engage and produce concussion, or byallowingit to retract, which stops the motion, so that by the use ofthis device, while the shaft is under constant motion, the operator canapply the concussion to the filling, can stop to insert the filling oradjust the same, or can use the plugger simply to produce hand pressureon the filling, as the exi- This obviates the great gencies may require.objection to those pluggersr which are operated directly from the dentalengine, but have no engaging and disengaging device by which the motioncan be controlled. This arrangement enables the operator to stop theconcussionsof the mallet, and to pick up and carry the gold to thecavity with the instrument, and to press the gold into the cavity 7o thekey-piece K is slightly tapering or wedging, so that it takes up thewear on the under side of the tool-stock I, and also the wear upon thekey itself, by which means the parts will always be kept tight.

I am aware that in Patent No. 162,154 is shown a cam-ring operated uponby a springplunger. In Patent No. 156,796 is shown a tool-shank havingan offset lug, which turns into a side notch, and is secured by a slide;and in reissued Patent No. 7,107 is shown a socket or holder at the endof the case for receiving the tool-shank. Such devices I eX- presslydisclaim.

What I claim as new is- 1. In a combined burring and plugginginstrument, the combination, with the revolving spindle and the malletresting and sliding thereon, of an engaging and disengaging device underthe control of the operators iin ger, so arranged, as described, that inits normal position 4it allows the spindle to revolve free and withoutgiving motion to the pluggingtool, but when pressed inward it engageswith the mallet and causes the mallet to produce concussions to operatethe plugging-tool, as herein set forth.

2. In a combined burring and plugging instrument, the combination of arevolving spindle extending through or nearly through the case, a malletresting on and turning with the spindle, but having a free slidingmovement endwise, a cam at the end of the mallet, and an engaging anddisengaging device outside the case, with which the cam engages whensaid device is pressed inward, as herein shown and described.

3. In a combined burring and plugging instrument, the combination, withthe nut G, screwing upon the spindle B and compressing the spring E, ofa slot, c, formed in the nut, and a spring, H, outside the case,provided with a lug, d, which, when pressed inward, engages with theslot and holds the nut stationary, while the spindle revolves within itto move it forward or back, as herein shown and described.

4. The combination, with the slotted spindle B and hollow mallet D, ofthe separate keypiece K, attached to the mallet and sliding in the slotof the spindle,as herein shown and described.

5. The combination, with the tool-shank I, provided with the offset lugg and flattened end h, of the corresponding offset notch 7c in thespindle, to receive the lug g when turned therein, to prevent the toolbeing drawn out, and the key-piece K, provided with the wedge- ICO IIO

IIS

a barring-tool may be inserted `in the end of the spindle, without theuse ot extra parts, as herein shown and described.

In lWitness whereof I have hereunto signed 15 my name in the presence oftwo subscribing Witnesses.

HENRY S. MILLER.

Witnesses:

UHAs. F. SPENCER, R. F. OsGooD.

